Aliphatic trithiocarbonates



Patented Feb. 28, 1950 ALIPHATIO TaITHIocAa onaT s Darwin: E. Badertscher and Charles 'En Beasley; v Woodbury, and Henry Q. Berger Glenltock,

N. J., a ssignors to socony vacu pany, Incorporated, a corporatio No-,;Drawing. Qriginal application August 30; 1845,; Serial No.;. 613304. Divided 'andwthis ap.-, nlicationJanharyZt 19.45, er a No-l '1 2;e90.4 r

This invention has to. do .-with v the treatment of hydrocarbon products such fa s mineralf oils to improve their characteristics, and morevspe cifically to the addition to. petroleum'lubricating l oilsof characterizingnagents whichimprove their, 5 ability to resist the deteriorating effect of. oxidag tion and their ability to lubricate bearing surfaces which are subjected to extremepressures such as are a now commonly encountered in hypoid gears and the like.

Moderatel r efin dc i a uch -asctq sa d other moderately refined lubricating oil nor mally used under conditions of exposure to oxidation in the presence of metals, oxidize to udge nd/Pa l. eiq a XiQa iQa aminate. mo alls, r s etc hicime e hi e her ns counter in use, as, for example, bea ingnnetals in automotive use. It has now been foundthat stabilization of: these oilstagainstwsuch oxidation effects may- -be conveniently accompl-ished by i ad,- dition to the'oils'of certain materials which -subz-a stantially-retardthe oxidation of the'oi-ls, whether, oranot metal "is present, o1 -byr.-the addition Off certain other-. materials which apparently have the-ability to inhibit the catalyticeffec tl oi -met g5 alainpromoting" oxidation reactions and th ustprevent the formation ofsludge and/or acidic.- constituents and= the like under normal condi tions-oi? use-'and achieve an-equallygoodpracticalresult; although-materials :otcthe latter-class mayt be -incapableof inhibitingmxidation of oils-in the absen ce ofmetals; This=-in-vention..has to do with: stabilizing reaction products which appean tcbe of thisJatterclass; not h'eretofore known. to be efiective for- :this purpose; and with mils stabilized-by the-useof these-reaction products;

Recent changes in automotive engine design; tending-toward-higher bearing pressures higherf. rota-tive speeds-,-higher engine-temperatures, etc i have been concurrent with markedadvances in 40 methods of -refininglubricant oils for automotive use. The demand foroils having lesser changes in viscosity- -with temperature-r change,- that. is, higher viscosity index; commonly-referred toas V'; 1:, has been met byrefining.-. lubriczmts -in- V tended fonmotoroi-ls by certainsolyent refining- 1 or; solvent: extraction processes; Certain liquidg reagents possesssolvent -power I forehydrocaxfbons of various types; as forexample, dichlorodiethyl x ether-,- cresylic acid; phenol, chloraniline, chloro- 50 phenol, phenetidine, benzyl; alcohol, nitroben-zene,- benzonitri1e,-'fur f-ural,1aniline, benzylacetate; liqst: l lp ur x i mix es;; of---*liqu-ic; i-s iphmia -,idezan inew th El e n w centrat inthe-desir v t i f irfii f co y, with-(changes. of. temperature, Tan d e t rei I are spoken of" as E (extremeapressurey-basesg 2 thegab ility "to, suiIer. -only a sma1l change of vise,

ti e omp eds-0 bhh nict-netn whic I do ,sufier such. fclr iarige of,. visc osit t I are-ed d em i fiSelrefi i g, p ooessesfha provide d a,snpply of an, oil of; quite desirab ene ah 'ha actr t s:= n e yg ar u r; any oil previously produced, from mixed. r, ra phalti dcss id u er e qa it t h r a er; de ree V .1 oils previously produced fro A;- par fl n basewr tz ass niound hathe so v refin new to the newezu bearin met als referred to,,aboy nder rmakcqnditmn pr i tom t v se. u to, oxidation during zyuse, sometimes resulting a r rmal driying', It;is fnrther known that the;

titan that is o r i 1o -be n n sQQdcPara i-nm base, 5 :W ch r t-whee teat-to s yen her. design-toward lowelizbodysty1es,- rapid accelerave, nd the use; of hypoidgears has increasedg 'thefiuniit loadings-on rear axles. In. some cases-1; the unit pressures encountered zbecome great;- enough to rupture the oil film of ordinary mineral oil lubricants,- "with consequent metal to metal; contact:- Inother 7 lines -'of "power trans mission 'and =the 1ike, there. is a similar-tendency towardthe.--use of high unitpressures of.a degree; which are; nearer or beyond I the limit at; which; mineral? oi1s,- alone,-- will" maintain efiective rlu l brication: The present inventionis, therefore; specifically concerned'with the productionof 1.11mi:v

bricants .,-capab1e;-=of "withstanding s the high 1mm loadingswhich occurs-in such instances. Such; lubricants are generally referred to as extremal pressure, -agents;-

Lubricants f of the. extreme pressure type area normally producedby addingto a hydrocarbon lubriatingoil a: small amount of some charac terizing substance which enables itto maintain: a lubricants filmhunruptuired'under conditions which would cause the breakdown of a filinzuclwddit r bstanc bases are composed 0;; $1115 conditions of high loading. It is an object of this invention to prepare novel and valuable ingredients and to combine them with hydrocarbon lubricant oils to produce'lubricants having high load bearing capacities, to prepare such ingredients which have good' characteristics of stabil,- ity, and which are less corrosive than ordinary extreme pressure ingredients. are the provision of methods of preparing lubricants containing these novel characterizing ingredients and methods of lubrication making use of the lubricants so produced. 7

Further objects after by representative test data.

Compounds characterized by two tertiary alkyl groups, R. and R are outstanding when used in oil in smal1 amounts, as demonstrated herein- Inasmuch as these compounds are believed to be new and novel, they are also contemplated herein as new compositions of matter.

A typical and direct method of preparation of these compounds involves reaction of an organic' dihalide and a mixture of a mercaptide and a thiocarbonate salt, as indicated in the following equation:

It is an important object of this invention to I provide means for satisfactorily inhibiting or preventing corrosion from taking place to a serious degree particularly in oils of relatively high viscosity index. It is also an object of this invention to provide a substantially non-corrosive motor oil of high V. I. Still another object of the invention is to provide an additive reagent, or ingredient capable of inhibiting the corrosive properties of these oils. The production of solvent refined oils of low corrosive properties under conditions of automotive use is a major object of this invention, as well as the method of production of such oils which combine a relatively high viscosity index with a relatively low tendency to produce such corrosion.

A further object is the provision of a method of-lubrication making use of oils containing these novel ingredients.

The present invention is predicated upon the discovery that hydrocarbon oils can be stabilized against the formation of acidic and/or corrosive bodies by oxidation in the presence of metal by the addition to said oils of a-relatively small amount of a novel compound represented by the following general formula:

R'--AR --B-R wherein R and R are monovalent hydrocarbon groups such as alkyl, alkenyl, cycloalkyl. cyclo alkenyl, aralkyl, aralkenyl. alkaryl, alkenaryl,

X-RzX+R1A-Na+R:-SNa

' R1--AR2SR3 ZNaX wherein X is a halogen atom.

This method is illustrated by the following examples:

EXAMPLE I (a) Preparation. of a sodium tertiary butyl thiocarbonate-sodium tertiary mercaptz'de equimolar mixture A solution of 600 grams of tertiary butyl mercaptan in 3,000 cc. of benzol was treated by addmg dropwise thereto 281 grams of 95% sodium- 80-85 C. with water removal for 13 /2 hours by heating the flask with a hot water bath. The water take-oil was replaced by a condenser after cooling the flask to about 10 C. and thereafter 900 grams of carbon disulfide were slowly introaryl. heteryl, etc, and at least one such roup,

either R or R is a tertiary alkyl group; R is a divalent hydrocarbon group of the aforesaid type (R' and R or a substituted group thereof such as'a halo en-s bstituted alkyl group. an ether group, a thioether group, etc. A represents a thiocarbonate group. either mono-, dior tri- Typical of the compounds represented by the general formula are the following:

(HsC)=Cs-C2H4S--(fi- S-0 H;

duced to the stirred suspension. The reaction mixture was then refluxed at 5060 C. for two hours and then allowed to cool. mixture was filtered, and the filtrate therefrom was washed with petroleum ether whereupon a light yellow powdery material was obtained. This material contains 41.4% sulphur as compared with the calculated value of 42.7% for a equimolar mixture of the mercaptide and trithiocarbonate.

(b) A solution of SlO grams of equimolar mixture prepared in (a) above; in 1,600 cos. of isopropyl alcohol was refluxed at 8287 C. with 1'73 grams of 18,5 dichloro-diethyl ether for a period of 8 hours whereupon a salt was formed. The

salt formed was removed by filtration and washed with hot isopropyl alcohol. The alcohol solution from the washing procedure and from the reaction filtrate was diluted with an equal Volume of water to cause a direct separation of a reddish oil as a lower layer. The upper and aqueous layer was extracted also with petroleum ether and these extracts were added to the original recovered red oil. The combined red oil solution was then distilled to a maximum liquid temperature of C. at 20-30 mm. to remove petroleum ether and other volatile impurities. The final product was a red voil weighing 245 grams, corresponding to a 48.9 per cent yield based on chlorex used. The oil The reaction grams of ethyle'ne" dichloride: The-rea=ction mix i ture' -was heated by a hbt water-bath -and vigor ously stirred by an electrically driven stirrer: The reaction: mixturewase warmed SW1y3t0J1-the reheatingait to' 1 75 C. for- 22' hours :whilea stream i. ofair 'was bubbled againstw the--surfakces of .tH bearing. The loss i'ri' weight 'of the 'bearingdur inesthis treatment-measures the 'amo'unt'of cor flux temperature, 82-87 0., andgwas refluxed for ros'ibfftbhat iihagstgken iplgjca sx m es frsm q hours. The reactionmixturewas fllteredwhile warm in orderto"removesalt"which"separated therefrom; and thefilti ate-wasseparated into twolayers, a, lower brine layer and an upper isopropyl alcohollayeppontaining thea'eaction prodnot. The isopropyl'alcoholsolution or layer was. heated and stir reilto.reinovemostof the isopropyl alcohol. The concentrated'product was waterwashed and thereaftemdistilledwto'sa, maximum. temperature of 130 C. at 20'mms., with nitrogen gas b'eing 'us'ed'to' sweepwut thevaporsa The: residue, the non-volatile portioni was. chilled'toc on eemammga cha raeteriz'ing compcundwas ru at thefsameftirne as a sample of-"thestraight" and tlieeldss in: weight zof the Q'bearin'g "section thei' irihiriitid "oil could thus be "compared" '"di'rectl with the loss of the'sectidnin-theuninhibitedoi The oil'used consisted of a PennsylVaniameutral 5 C. whereupon yellow crystals separated therefrom. These crystals were removed by filtration thereby providing a filtrate and the yellow crystals. The filtrate contains 44.9 per cent sulphur as against 45.6 per cent sulphur. calculated for (HaC)3CSCS2CH2CH2SC(CH3)3. The yellow solid was recrystallized from Stoddard solvent, washed with petroleum ether and distilled under vacuum to remove said solvent and ether. The purified yellow solid contained 54.3 per cent sulfur and had As hereinabove mentioned, the novel compounds contemplated herein are effective extreme pressure (E. 1?.) agents. Oil blends containing typical characterizing compounds were subjected to the Almen pin test (described by Wolf and Mougey, Free. A. P. I. 1932, pp. 118- and the SAE test (described Anon S. A. E. Journal 39, 23-4, 1936) with the results as shown The proportion of the characterizing compounds of this invention used in admixture with ordinary hydrocarbon oils may be varied considerably. Generally, concentrations of from about 0.05 per cent to about per cent of the compounds effectively stabilize the oils in which they are used. Ordinary hydrocarbon oils are effectively fortified to withstand extreme pressure conditions now encountered in hypoid gears and the like, when concentrations from about 5 per cent to about 15 per cent are used. In general; then, these compounds are used in amounts ranging from about 0.05 per cent to about 15 per cent depending upon the oil used and the improvement desired. Further, these characterizing compounds may also be used in oil in combination with other oil-addition agents such, for example, as pour point depressants, viscosity index improving agents, other antioxidants such, for example, as phenols, amines, etc.

This application is a division of application Serial Number 613,704, filed August 30, 1945.

It will be understood that the present invention is not restricted to the details of the foregoing examples which are presented herein to wherein R and R are monovalent tertiary 3. As a new. composition of matter, the compound:

DARWIN E. BADERTSCHER. CHARLES F. FEASLEY.

HENRY G. BERGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 

1. AS A NEW COMPOSITION OF MATTER, A COMPOUND REPRESENTED BY THE GENERAL FORMULA: 